261055340 has 144 divisors (see below), whose sum is σ = 710002944. Its totient is φ = 79833600.

The previous prime is 261055337. The next prime is 261055351. The reversal of 261055340 is 43550162.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 394610 + ... + 395270.

It is an arithmetic number, because the mean of its divisors is an integer number (4930576).

Almost surely, 2^261055340 is an apocalyptic number.

261055340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261055340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (355001472).

261055340 is an abundant number, since it is smaller than the sum of its proper divisors (448947604).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261055340 is a wasteful number, since it uses less digits than its factorization.

261055340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 728 (or 719 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 26.

The square root of 261055340 is about 16157.2070606278. The cubic root of 261055340 is about 639.1128169582.

The spelling of 261055340 in words is "two hundred sixty-one million, fifty-five thousand, three hundred forty".